Socioeconomic inequalities in health during early childhood: Evidence from a birth cohort

Abstract

Introduction Biological and social capital is essentially acquired in early childhood, so measuring socioeconomic inequalities in health this early is of huge relevance. On this topic there are important scientific gaps: scarcity of studies from Southern Europe, reliance on single indicators of socioeconomic position (SEP) and on self-reported data. We aimed to measure socioeconomic inequalities in health during early childhood and address the following research questions: –do socioeconomic inequality measures depend on the SEP indicators that were used?; –are children's health outcomes socially patterned, and if so, in which direction?; –do some health outcomes manifest wider socioeconomic inequalities? Methods Data on early childhood (4 years of age) health was obtained from Generation XXI birth cohort (n = 8647). A total of 27 health outcomes and 13 SEP indicators at the individual and neighbourhood level were used to calculate relative risks of inequality (RRI) and corresponding 95% confidence intervals. Results Twenty-one, out of 27 health outcomes evaluated, showed significant socioeconomic inequalities. Using the highest education level of the mother as reference, we observed that seizures (RRI = 8.64), obesity (2.94), abdominal obesity (2.66), urinary tract infection (2.26), language/speech developmental problems (2.24), hypertension (2.08) and insulin resistance (1.33) were heavily socially patterned, much more common in low SEP children. Several outcomes followed reverse patterns, namely eczema (0.26), rhinitis (0.26). Most infections, accidents, and some blood parameters showed less clear and narrower inequalities. Education, occupation and household income captured more often inequalities, as compared with neighbourhood deprivation or parental employment status, which were barely associated with children's health. Conclusions Socioeconomic inequalities were evident in almost every health outcome, although with varying magnitude according to the SEP indicator and health outcome. Reverse socioeconomic gradients were identified too. Our results reinforce the importance of tackling health inequalities early in life and suggest that actions should be designed to target all societal groups, the most but also the least disadvantaged.